Math

GCD & LCM Calculator

Calculate GCD and LCM for a comma- or space-separated list of positive whole numbers using the Euclidean algorithm.

The greatest common divisor (GCD) is the largest positive integer that divides every entered number. The least common multiple (LCM) is the smallest positive integer divisible by all of them.

GCD helps simplify fractions and ratios; LCM helps align repeating cycles and add fractions with different denominators.

Frequently asked questions

Can I enter more than two numbers?

Yes. Separate positive integers with commas, spaces, or semicolons.

What is another name for GCD?

It is also called the greatest common factor or highest common factor.

Can the LCM be smaller than an input?

For positive integers, the LCM is at least as large as the largest input.